feat(cv): Phase 2.1-b — extract Projects, Certifications, and languages-from-prose

The structured model and StructuredCvProfileJson.FromSections already map
Projects/Certifications/Languages headings, but the AI normalize prompt
never emitted them, so on the benchmark CV the entire Projects section and
the in-summary languages (English Native, Norwegian B1) were silently
dropped. This closes that gap upstream — no backend schema or data change.

ai-service (tools/summarizer/app.py):
- /cv/normalize: added # Projects and # Certifications headings; a
  languages-from-prose rule (pull "native English", "Norwegian at B1" out
  of the summary even with no Languages section; ignore programming
  languages); and skill-group prefix stripping ("Development:",
  "DevOps & Infrastructure:", "Practices:" dropped, only the skills kept).
- /cv/classify-block: Projects and Certifications added to the section
  enum + rules (fallback path).

Backend:
- LooksLikeNormalizedMarkdownCv now recognises # Projects / # Certifications
  so those CVs still take the markdown assembly path.

Tests:
- CvExtractionCoverageTests (4) lock the C# mapping of Projects,
  Certifications and Languages sections into the structured profile.
- ai-service test_classify_block_supports_projects_section (1).
426 backend tests, 17 ai-service tests pass; app.py compiles.

The LLM behaviour (prompt -> headings) needs Ollama to observe and was not
run here; the C# side that consumes the headings is proven and the prompt
change is additive. Merge-not-replace + the review screen are the next
increment (2.1-a, approved: always-review, conservative merge).

Deployment: these prompts live in the ai-service container, which
deploy.sh does not rebuild by default -- deploy with
DEPLOY_BUILD_AI_SERVICE=true or the change won't take effect.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

JobTrackerApi/Controllers/ProfileCvController.cs

@@ -2124,7 +2124,7 @@ public sealed class ProfileCvController : ControllerBase
     private static bool LooksLikeNormalizedMarkdownCv(string text)
     {
         if (string.IsNullOrWhiteSpace(text)) return false;
-        return Regex.IsMatch(text, @"(?im)^#\s+(Contact|Professional Summary|Work Experience|Education|Skills|Languages|Interests)\s*$");
+        return Regex.IsMatch(text, @"(?im)^#\s+(Contact|Professional Summary|Work Experience|Education|Skills|Languages|Interests|Projects|Certifications)\s*$");
     }
 
     private static StructuredCvProfile BuildStructuredCvFromNormalizedMarkdown(string text)